Electrical apparatus



May 29, 1934- F. M. EDWARDS 1,960,579

ELECTRICAL APPARATUS Filed Dec 19, 1930 2 Sheets-Sheet 1 l 'f III-MMmimi" INVENTOR May 29, 1934. M EDWARDS 1,960,579

ELECTRICAL APPARATUS Filed DeC. 19. 1950 2 Sheets-Sheet 2 INVENTOR 5F50M52 vnf/7F05.

ATTO Y Patented May 29, 1934 UTED STATES ELECTRICAL APPARATUS'y Fred M.Edwards, Oak Park, Ill., assigner to" Grigsby-Grunow Company, Chicago,Ill., a corporation of Illinois; Frank M. McKey, receiver in bankruptcyApplication December 19, 1930, Seriall No. 503,430

7 Claims.

This invention relates to electrical apparatus and particularly to radioreceiving sets. In the manufacture of such sets, it is highlyadvantageous to have a structure which will be compact, sturdy and becapable of withstanding the abuse incidental to assembly duringmanufacture.

An object of this invention is to devise a structure of the abovecharacter which will satisfy the above requirements.

In the drawings, Figure 1 is a perspective View from the front of aradio chassis embodying this invention.

Figure 2 is a similar View from the rear of the chassis.

Figure 3 is a perspective view of a sub-assembly formers.

Figure 4 is a perspective view of the assembly of Figure 3 in invertedposition.

Figure 5 is a perspective View of the audio frequency tube mounting.

Figures 6 and 7 show the cover and gang condenser respectively.

'Ihe chassis comprises a base member 1 of sheet metal having up-turnedtriangular flanges 2 and 3 at each side thereof. Dividing base member 1at the longitudinal center line is a vertical partition 4 havingsimilarly projecting sides 5 and 6 and forming a generally U shapedstructure. As shown in Figures 1 and 2, sides 5 and 6'of partition 4engage upstanding flanges 2 and 3 of base member 1 and are boltedtogether at 7.

The entire radio frequency and audio frequency parts of a complete radioreceiver including a power supply are mounted on both sides of partition4. Looking from the front of the chassis, as in Figure 1', a gangcondenser, generally designated as 10, of well-known construction ismounted on partition 4 approximately centrally disposed with respect tothe sides of the chassis. A protecting cover 11 is provided for gangcondenser 10. At one end of gang condenser 10, there is disposed anoperating assembly therefor comprising a projecting shaft 12, suitablyYconnected to the shaft of gang condenser 10. This mechanism, which iswell known, includes an indicating dial 13 for showing the position ofthe condenser gang.

Disposed on the opposite side of partition 4 is the remaining portion ofthe radio frequency elements shown in Figures 3 and 4 and generallydesignated as 15. It will be noted that subassembly 15 comprises agenerally rectangular sheet metal member 16, having one downwardly bentside wall 17 and an end member 18 projecting (Cl. `Z50-44) on both sidesof member 16. Suitably mounted on member 16 are a plurality of vacuumtube sockets 2O for radio frequency or, if a superheterodyne circuit isused, intermediate frequency amplifiers. Below tube sockets 20 and onthe inside of wall 17 may be disposed small fixed condensers, such as 21radio frequency chokes from the power supply or any similar elementswhich are to be connected in the tubel circuits. Tube sockets 20 areadapated to support tube shields 22, covering vacuum tubes 23. Bolted tosheet member 16` is a rectangular box-shaped member 25 within which maybe disposed various radio frequency transformers necessary for theproper operation of the set. In this instance, a superheterodyne circuitis used and the intermediate frequency transformers are housed withinbox 25. Adjacent to box 25 and in line therewith on member 16 may bemounted additional apparatus 26 and 27 comprising such radio frequencytransformers as must be disposed in close proximity to certainparticular tubes or condensers. Thus, in this instance, withindome-shaped metal member 26 is mounted the inductance units of anoscillator, the capacity of which is furnished by one of the gangcondensers. Member 27 may be one of the radio frequency transformersahead of the first detector.

It will be noted that the various edges of the units are suitablyflanged and apertured so that they may be'bolted in their respectivepositions. Since gang condenser 10 is disposed in close proximity to theremaining high frequency apparatus on the other side of partition 4, itis evident that an efficient and compact arrangement of the highfrequency elements is possible. Various shielding plates and members maybe disposed to protect the elements from each other. It will be notedthat the assembly generally designated as 15, in Figures 3 and 4, is acompact, selfcontained unit which may be assembled' separately and thenincorporated on the chassis.

Disposed between side 6 and assembly 15 isa power transformer 30 adaptedto transform alternating current from the lighting circuit into currentsat Various voltages for supplying the necessities of the variousamplifiers. Disposed on the other side of partition 4 is a can 31containing a plurality of chokes for filtering the plate supply currentfrom transformer 30. On the same side of partition 4, but on the otherside of the chassis is a can 32 containing the condensers for the filtercircuit. Disposed above cans 31 and 32 on partition 4 are'cans 33'and 34containing audio frequency transformers.

. condenser,

On the other side of partition fi, above transformer 30, there is boltedto the partition a metallic rectangular can containing a plurality oftube sockets 36 for the rectiiier and audio frequency tubes. Within thiscan may be disposed bias resistors and other small elements associatedwith audio frequency ampliers. A suitable cover plate 40 is bolted tothe open side of said can and serves to give ready access to the wiringof the audio frequency amplifier.

The output of the audio ampliners may be fed to any type of loudspeaker, which is here shown as mounted at the upper central portion ofpartition 4.

It will be noted that the heavy pieces of apparatus, such as powertransformer, inductances, filter condensers and audio frequencytransformers are mounted in such a way so that the chassis ismechanically balanced. In addition, the radio frequency elements of theset are closely adjacent each other to reduce losses. By making base 1and partition 4 of heavy metal, it is possible to obtain a chassis whichhas compactness and sturdiness combined to an unusual degree.

It is, of course, possible, to re-arrange certain of the elements,particularly the audio frequency elements without departing from thespirit of this invention. Furthermore, certain radio frequency elements,such as input coils, may be disposed wherever convenient. Where the termradio frequency elements is used, it is understood that intermediatefrequency apparatus of a superheterodyne circuit is to be included.

. What I claim is:

1. A complete radio receiving set chassis comprising a metallic basemember, a metallic vertical partition member dividing said base vmemberinto substantially equal portions and rigidly secured thereto a gangcondenser mounted on one side of said partition member, substantiallyall of the remaining radio frequency elements mounted on the other sideof said partition member in close proximity to said condenser, audiofrequency and power supply elements secured to said base member andpartition on both sides of Ysaid partition, and a loud speaker mountedon said vertical partition at the upper central portion thereof.

2. A radio receiving set chassis comprising a metallic horizontal basemember, a metallic vertical partition member dividing said base memberinto substantially equal portions, a gang condenser secured to saidpartition member on one side thereof, substantially all remaining radiofrequency elements secured on the other side of said partition and inclose proximity to said gang audio frequency transformers and powersupply elements disposed at each end of said gang condenser on the sameside of the partition member in balanced relation, remaining audiofrequency and power supply elements mounted on the other side of saidpartition member from the gang condenser, and a loud speaker mounted onsaid vertical partition at the central upper portion thereof.

3. A radio receiving set chassis comprising a metallic ybase member, ametallic partition member rising vertically from said base memberrigidly secured thereto and dividing said base member into substantiallyequal portions, a gang condenser secured to an intermediate portion ofsaid partition member, audio frequency transformers and lter elements ofthe power supply circuitsecured to said partition member on the sameside as said gang condenser, additional radio frequency elementsincluding tube mountings secured to said partition member on the sideremote from said gang condenser and in close proximity to the latter,and additional audio frequency and power supply elements including tubemountings secured on the same side of said partition member saidpartition member having its ends extended and bent at right angles alongthe sides of said base on the same side of said partition, and enclosingthe apparatus on one side of said partition.

A radio receiving set chassis comprising a metallic base member, ametallic vertical partition member rigidly secured thereto and dividingsaid base member into substantially equal portions, a gang condensersecured to said partition member substantially midway between the sidesof said partition, audio frequency transformers and choke and condenserelements of the power supply filter circuit secured to saidpartitionmember on the same side thereof and at each end of said gang condenser,additional radio Vfrequency elements including tube sockets mounted onthe other side of said partition member in close proximity tosaid gangcondenser, additional audio frequency elements including tube sockets,power supply elements mounted on the last named side of said partitionmember and a loud' speaker mounted at the central upper portion of saidpartition member.

5. A radio receiving Vset chassis comprising a metallic base member, ametallic vertical partition member rigidly secured thereto and dividingsaid base member into substantially equal portions, a gang condensersecured to said partition member substantially midway between the sidesthereof and at the lower portion, audio frequency transformers and powersupply lter elements secured to said partition at the ends thereof andon the same side as the condenser, a loud speaker secured to saidpartition at the upper central portion thereof above said condenser andon the same side thereof, and remaining radio frequency, audio frequencyand power supply elements including tube sockets mounted on the otherside of said partition said partition member having its ends extendedand bent at right angles thereto along the sides of said base on theside of said partition where the tube sockets are mounted, and enclosingthe apparatus on that side of the partition.

6. A radio receiving set chassis comprising a metallic base member, avertical metallic partition member rigidlylsecured to said base memberand dividing said member into substantially equal portions, a gangcondenser mounted to the lower central portion of said partition, chokeand inductance elements of a power iilter circuit mounted to saidpartition on each side of said condenser, a loud speaker mounted to saidpartition above said condenser, audio frequency transformers mounted onsaid partition on each side of said speaker, substantially all remainingradio frequency elements mounted on the other side of said partition andin close proximity to said gang condenser, and the remaining elements ofthe set including tube sockets mounted on said other side of saidpartition.

7. A radio receiving set chassis comprising a metallic base memberhaving upstanding sides, a vertical metallic partition member rigidlysecured to said upstanding sides and dividing said base member intosubstantially equal portions, a gang condenser mounted on the lowercentral portion of said partition, choke and condenser elements of apower suppIy filtering circuit mounted to said partition on each side ofsaid condenser, a loud speaker mounted on said partition above saidcondenser, audio frequency transformers mounted to said partition oneach side of said speaker, a power supply transformer mounted on theother side of said partition, an audio frequency tube assembly mountedon said other side of the partition above said power transformer andremain-

